We have discovered that TF is not mere assay artifact; we show that TF is derived from antigen-specific CD8+ memory T-cells, acts upon APCs to induce IL-6, and subsequently stimulates memory Tc17 activity to enhance responses in mucosal challenge models for both mice and humans. We found that the molecule responsible for these effects is larger than previously reported. We obtained partial sequencing of TF, with analytical chemistry evidence suggesting a hybrid molecule of S100 peptides and the beta chain of the TCR.